Wire wound tooling

ABSTRACT

Tool rolls and methods of using the tool rolls to manufacture articles with one or more structured surfaces are disclosed. The tool rolls include an outer surface that, when used in connection with materials of the proper viscosity or formability, can form a structured surface on an article. Because the tools are manufactured in roll-form, they can be advantageously used in continuous manufacturing processes. Alternatively, discrete articles may be processed using the tool rolls. The tool rolls are constructed of a cylindrical base roll and are wrapped with one or more continuous wires in a helical pattern. The wires are used, in essence, to form a structured surface on the tool roll that is the negative of the structured surface to be formed on the articles processed using the tool roll. One of the wires wound around the base roll may include depressions formed therein that, when wound in helical coils about the base roll, form cavities on the outer surface of the tool roll. Alternatively, the helical pattern of one or more wound wires may be used to form a continuous helical structured surface, e.g., a helical groove or grooves.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.11/101,706, filed Apr. 8, 2005, now allowed, which is a division of U.S.patent application Ser. No. 10/438,082, filed May 14, 2003, issued onJun. 7, 2005 as U.S. Pat. No. 6,902,389.

FIELD OF THE INVENTION

The present invention relates to the field of manufacturing articleswith structured surfaces. More particularly, the present inventionprovides tooling for manufacturing articles with one or more structuredsurfaces, methods of manufacturing the tooling, and methods of using thetooling to manufacture articles with one or more structured surfaces.

BACKGROUND

Articles with one or more structured surfaces find a variety of uses.The articles may be provided as films that exhibit, e.g., increasedsurface area, structures used to provide a mechanical fastener, opticalproperties, etc. When these films are manufactured for use as mechanicalfasteners, the protrusions that are found on the structured surface arecommonly referred to as hooks. The hooks may be formed in a curved shapeor they may be substantially upright stems that are deformed to include,e.g., a head in the shape of mushroom.

Mechanical fasteners are sometimes designed so that two hook strips canbe used to fasten two articles together by adhering each strip to one ofthe articles and then interengaging the two strips. Such a mechanicalfastener is shown in U.S. Pat. No. 3,192,589 (Pearson) which calls thefastener “hermaphroditic” because its headed studs have both male andfemale characteristics when intermeshed. The Pearson fasteners can bemade by molding a base from which integral headless studs project andthen heat softening the tips of the studs.

U.S. Pat. No. 5,077,870 (Melbye et al.) discloses one method ofmanufacturing the hook strip portion of a mechanical fastener by forcingmolten material into cavities formed in a moving mold surface. The stemsformed by the moving mold surface are then capped to form the desiredfasteners. The cavities are formed in the mold surface by drilling. As aresult, the cavities are cylindrical in shape and, although someprecision can be obtained in depth, diameter and spacing betweencavities, it is obtained with some difficulty and increased costs.Furthermore, damage to the mold surface typically requires that theentire mold be discarded.

U.S. Pat. No. 5,792,411 (Morris et al.) discloses a molding toolmanufactured by laser machining a mold surface. Molten material is thenforced into the cavities in the moving mold surface to form stems. Thestems are then capped to form the desired fasteners. Because thecavities are formed by laser ablation, the cavity shape is based on theenergy distribution within the laser beam used to form the cavities.Furthermore, precise control over the depth of the cavities is difficultto obtain due to variability in the material used to construct the mold,the power of the laser beam, the energy distribution within the beam,beam focus, etc.

U.S. Pat. No. 4,775,310 (Fischer) and PCT Publication No. WO 97/46129(Lacey et al.) disclose tooling used to manufacture hook strips for ahook-and-loop style mechanical fastener. The tools are formed by ahollow drum with a water cooling jacket. A series of mold disks oralternating mold disks and spacer plates are laminated together alongthe length of the drum to form the desired mold cavities on the face ofthe roll. Disadvantages of these designs include the cost ofmanufacturing the mold disks with adequate precision to ensure that themold cavities are of the same depth, length, spacing, etc. Sizelimitations imposed on the disks by manufacturing difficulties can, inturn, limit line speed in processes using the tools. Other disadvantagesof this design include non-uniform cooling of the mold cavities,non-uniformities in the products produced by the stacked plates, etc.

SUMMARY OF THE INVENTION

The present invention provides tool rolls and methods of using the toolrolls to manufacture articles with one or more structured surfaces. Thetool rolls include an outer surface that, when used in connection withmaterials of the proper viscosity or formability, can form a structuredsurface on an article. Because the tools are manufactured in roll-form,they can be advantageously used in continuous manufacturing processes.Alternatively, discrete articles may be processed using the tool rollsof the present invention.

By “structured surface” it is meant that a surface of the articledeviates from a planar or other smooth surface. For example, thestructured surface may include protrusions extending therefrom, such asstems used in connection with mechanical fasteners. Other alternativestructured surfaces include, but are not limited to: continuous groovesor ridges, elongated structures, etc.

The tool rolls of the present invention are constructed of a cylindricalbase roll and are wrapped with one or more continuous wires in a helicalpattern. The wires are used, in essence, to form a structured surface onthe tool roll that is the negative of the structured surface to beformed on the articles processed using the tool roll. In one embodiment,at least one of the wires wound around the base roll may includedepressions formed therein that, when wound in helical coils about thebase roll, form mold cavities on the outer surface of the tool roll.

Advantages of the tool rolls according to the present invention includethe ability to provide mold cavities with particularly small tangentialcross-sectional areas. Also, feature dimensions of the depressionsformed in the major sides of the wires may not be limited by, e.g., thethickness of the wire as with a wire including voids punched throughboth major sides. Mold cavities formed by depressions according to thepresent invention may be formed with depths that may extend over theentire side surfaces of the wires. As a result, protrusions may beformed using the tool roll that have a particularly high aspect ratio.

Filling of such high aspect ratio mold cavities may be enhanced by bleedstructures on the wires and/or the base roll. Those bleed structuresassist in the escape of air from the mold cavities during molding.

Another advantage of tool rolls according to the present invention isthe density at which the mold cavities may be provided on the outersurface of the tool roll. By forming the mold cavities from depressions,structural integrity of the wire may be enhanced as compared to moldcavities formed by voids punched through both major sides of a wire.That enhanced structural integrity may allow for closer spacing of themold cavities on the tool roll. The closer spacing of the mold cavitiestranslates into increased density in the features that may be formed onarticles manufacture using the tool roll.

Yet another advantage of tool rolls according to the present inventionis that one or more depressions in a major side of the wire may becombined with a void formed through a wire to form a composite moldcavity having a shape that is not possible with a void or depressionsalone.

Other advantages of the tool rolls include, but are not limited to theability to replace the wire windings on the base roll if the outersurface of the tool roll becomes damaged or worn. The tool rolls mayalso be relatively inexpensive as compared to the cost of manufacturingtool rolls using, e.g., stacked plates or direct drilling of the moldsurface.

Another advantage is the ability to control the spacing between moldcavities along the width of the roll by varying the thickness of thewire or wires wrapped around the base roll. Spacing of the mold cavitiesabout the circumference can also be independently controlled bycontrolling the spacing between depressions in the wire or wires wrappedaround the base roll. A further advantage is that, by controlling theprofile or cross-sectional shape of the wire or wires and the shape orshapes of the depressions formed in the wire, variations in the shape orshapes of the mold cavities can also be achieved.

Yet another advantage of the present invention is the relatively smallthermal mass of the wire or wires wrapped around the base roll incomparison to the thermal mass of the base roll. As a result, thermalcontrol over the mold cavities can be improved, which can result incorresponding improvements in the uniformity of the products producedusing the tool rolls.

As used in connection with the present invention, a “mold cavity” may beany discontinuity in an otherwise smooth or planar surface into whichmoldable material may flow during a molding process. In some embodimentsof the present invention, the tool rolls may include mold cavities withhigh aspect ratios as defined below, although it should be understoodthat a mold cavity need not have a high aspect ratio.

In one aspect, the present invention provides a tool roll with acylindrical base roll and a first wire having an inner edge, outer edge,and first and second major sides located therebetween. The first majorside of the first wire includes a plurality of depressions formedtherein and the first wire is wound in helical coils around the baseroll such that the inner edge is proximate the base roll. The pluralityof depressions in the first major side of the first wire form aplurality of mold cavities with each of the mold cavities including amold opening at an outer surface of the tool roll proximate the outeredge of the first wire.

In another aspect, the present invention provides a tool roll includinga cylindrical base roll and a first wire with an inner edge, outer edge,and first and second major sides located therebetween. The first majorside of the first wire includes a plurality of depressions formedtherein and the first wire is wound in helical coils around the baseroll such that the inner edge is proximate the base roll. The pluralityof depressions in the first major side of the first wire form aplurality of mold cavities with each of the mold cavities including amold opening at an outer surface of the tool roll proximate the outeredge of the first wire. The tool roll also includes a second wire withan inner edge, outer edge, and first and second major sides locatedtherebetween. The second wire is wound in helical coils around the baseroll such that the inner edge of the second wire is proximate the baseroll, wherein the second wire is located between adjacent helical coilsof the first wire. The first major side of the second wire includes ableed structure formed therein and an edge zone free of the bleedstructure.

In another aspect, the present invention provides a tool roll includinga cylindrical base roll and a first wire with an inner edge, outer edge,and first and second major sides located therebetween. The first wire iswound in helical coils around the base roll such that the inner edge isproximate the base roll. The first wire also includes a plurality ofdepressions formed in the first major side of the first wire and aplurality of voids formed through the first and second major sides ofthe first wire, wherein each of the voids includes a depressionextending therefrom. The plurality of voids with depressions extendingtherefrom form a plurality of composite mold cavities with each of thecomposite mold cavities having a mold opening at an outer surface of thetool roll proximate the outer edge of the first wire.

In another aspect, the present invention provides a tool roll includinga cylindrical base roll and a first wire with an inner edge, outer edge,and first and second major sides located therebetween, wherein the firstwire is wound in helical coils around the base roll such that the inneredge is proximate the base roll. The first wire also includes aplurality of depressions formed in the first major side of the firstwire. The tool roll further includes a second wire with an inner edge,outer edge, and first and second major sides located therebetween,wherein the second wire is wound around the base roll such that thesecond wire is located between adjacent helical coils of the first wire.The second wire includes a plurality of voids formed through the firstand second major sides of the second wire. The plurality of depressionsin the first wire and the plurality of voids in the second wire form aplurality of composite mold cavities, wherein each of the composite moldcavities includes at least one void of the plurality of voids, at leastone depression of the plurality of depressions, and a mold opening at anouter surface of the tool roll proximate the outer edges of the firstand second wires.

In another aspect, the present invention provides a method of forming astructured surface on an article, the method including providing a toolroll according to the present invention, contacting a moldable materialto the outer surface of the tool roll to form the structured surfaceusing the outer surface of the tool roll, wherein the moldable materialat least partially fills at least some of the mold cavities or compositemold cavities; and removing the structured surface from the outersurface of the tool roll, wherein the structured surface includes aplurality of protrusions corresponding to the plurality of mold cavitiesor composite mold cavities.

In another aspect, the present invention provides an article including abase surface, a plurality of elongated ridges protruding from the basesurface, and a plurality of ears protruding from each elongated ridge ofthe plurality of elongated ridges.

These and other features and advantages of the present invention aredescribed below in connection with illustrative embodiments of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of one tool roll including cavities formed thereinaccording to the present invention.

FIG. 1A is an enlarged perspective view of a structured surface formedusing a tool roll according to the present invention.

FIG. 1B is a photomicrograph of one article with protrusions formedthereon with the protrusions having been capped after formation.

FIG. 2 is an enlarged cut-away perspective view of a portion of thesurface of the tool roll of FIG. 1 illustrating the cavities formedtherein.

FIG. 3A is an enlarged plan view of the surface of the tool roll of FIG.1.

FIG. 3B is a cross-sectional view of FIG. 3A taken along line 3B-3B.

FIG. 3C is a cross-sectional view of FIG. 3A taken along line 3C-3C.

FIG. 4 is a plan view of another tool roll including cavities formedtherein according to the present invention.

FIG. 5 is an enlarged cut-away perspective view of a portion of thesurface of the tool roll of FIG. 4 illustrating the cavities formedtherein.

FIG. 5A is a plan view of another tool roll surface in which moldcavities are formed as composites of two depressions formed in wiresfacing each other.

FIGS. 6A-6F illustrate a variety of mold cavity shapes.

FIG. 7A is a plan view of a tool roll including circumferential areaswith different mold cavities.

FIG. 7B is a plan view of a tool roll including a longitudinal area withdifferent mold cavities.

FIG. 7C is a plan view of a tool roll including a logo with differentmold cavities in the area of the logo.

FIGS. 8A-8D illustrate different wire profiles for use in tool rollsaccording to the present invention.

FIG. 9 illustrates one method of manufacturing a tool roll according tothe present invention.

FIG. 10 illustrates one method of manufacturing a high aspect topologyfilm using a tool roll according to the present invention.

FIG. 11 is a cross-sectional view of the apparatus of FIG. 10, takenalong line 11-11 in FIG. 10.

FIG. 12 illustrates one method of manufacturing a high aspect topologyfilm including protrusions on both sides using two tool rolls accordingto the present invention.

FIG. 13 is a plan view of another wire wound tool according to thepresent invention including composite mold cavities formed by voids anddepressions in the same wire.

FIG. 14 is a perspective view of wire 820 from FIG. 13, depicting a voidand depressions formed therein.

FIG. 15 is a perspective view of one protrusion formed by the compositemold cavity of FIG. 13.

FIG. 16 is a side view of the protrusion of FIG. 15 after processing.

FIG. 17 is a plan view of another wire wound tool according to thepresent invention including composite mold cavities formed by voids anddepressions in different wires.

FIG. 18 is a cross-sectional view of wire 920 in FIG. 17 taken alongline 18-18, depicting a void in wire 920 and a depression in adjacentwire 940 a.

FIG. 19 is a cross-sectional view of FIG. 17 taken along line 19-19,depicting a major side of wire 940 a and a depression formed therein.

FIG. 20 is a perspective view of one protrusion formed by the compositemold cavity of FIG. 17.

FIG. 21 is a side view of the protrusion of FIG. 20 after processing.

FIG. 22 is a perspective view of a portion of one article according tothe present invention.

FIG. 23 is a plan view of a portion of one tool roll that can be used tomanufacture the article of FIG. 22.

FIG. 24 is a cross-sectional view of the tool roll of FIG. 23 takenalong line 24-24 in FIG. 23.

FIG. 25 depicts a tool roll with discontinuous helical grooves formed inits outer surface.

FIG. 26 is perspective view of an article manufactured using the toolroll of FIG. 25.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

The present invention provides tool rolls and methods of using the toolrolls to manufacture articles with one or more structured surfaces. Thetool rolls include an outer surface that, when used in connection withmaterials of the proper viscosity or formability, can form a structuredsurface on an article. Because the tools are manufactured in ro11-form,they can be advantageously used in continuous manufacturing processes toform e.g., films, sheets, etc. Alternatively, discrete articles may beprocessed using the tool rolls of the present invention.

The tool rolls of the present invention may include mold cavities intheir outer surfaces that, when used in connection with materials of theproper viscosity or formability, can form protrusions or structures onat least one surface of a film. Alternatively, two such rolls can beused in combination to form a film in which both major surfaces exhibitprotrusions or structures.

FIG. 1 depicts one illustrative embodiment of a tool roll 10 accordingto the present invention including mold cavities 30 opening into anouter surface of the tool roll 10. FIG. 2 illustrates an enlargedpartial cut-away view of the surface of the tool roll 10 of FIG. 1. Thetool roll 10 preferably includes a cylindrical base roll 12 around whichone or more wires are wrapped in the shape of a helical coil to producea surface having mold cavities 30 formed therein.

The wire or wires wrapped around the base roll 12 may be held in placeby any suitable mechanism, including, but not limited to clamps,welding, adhesives, etc. Such techniques are known in the production of,e.g., carding rolls. See, e.g., U.S. Pat. No. 4,272,865 (Schmolke).

One preferred application in which tool rolls manufactured according tothe present invention such as tool roll 10 may be used is in theproduction of high aspect topology structured surfaces. Referring toFIG. 1A, one illustrative article 70 formed using tool roll 10 isdepicted including a structured surface having protrusions 72 formedthereon. The illustrated protrusions have a height h′ above the surface74 of the article 70 and a minimum width w′ measured in a plane Igenerally parallel to the plane of the surface 74. If the surface 74 hassome curvature, the plane I is preferably oriented tangential to thesurface 74 in the area of the protrusion 72.

The protrusions 72 may have a high aspect ratio and the tool rollsaccording to the present invention may be particularly advantageous inthe manufacturing of structured surfaces with high aspect ratiotopologies. By “high aspect ratio” it is meant that the ratio ofprotrusion height to minimum width (h′:w′) at the base of the protrusion72 proximate surface 74 is, e.g., at least about 2:1 or higher, morepreferably about 3:1 or higher, and even more preferably at least about5:1 or higher. In addition to, or in place of, high aspect ratio asdefined above, it may be preferred that the protrusion or structureheight h′ above the major surface of the article be, e.g., about 0.1millimeters or more, more preferably about 0.2 millimeters or more, andeven more preferably about 0.4 millimeters or more.

FIG. 1B is an enlarged perspective photomicrograph of a portion of oneexemplary article manufactured according to the principles of thepresent invention. The article, which may be provided in sheet or filmform, includes protrusions that have been capped after formation with atool in accordance with the present invention. Such articles mayadvantageously be used as mechanical fasteners (e.g., mushroom-type orhook-type mechanical fasteners). If the article is used as a mechanicalfastener, the protrusions may commonly be referred to as stems, althoughuse of that term is not intended to limit the scope of use for thearticles manufactured using the present invention.

Although the articles that can be produced by tool rolls and methods ofthe present invention are advantageously used as mechanical fasteners,the articles may find a variety of other uses and the tool rolls andmethods of using the tool rolls to manufacture articles with structuredsurfaces according to the present invention should not be limited to thefield of mechanical fasteners. For example, the protrusions formed onthe structured surface of an article according to the present inventionmay provide advantages in retaining adhesives or othercoatings/materials by, e.g., increasing the surface area of the film.The structured surfaces formed by the tool rolls may also be useful fordecorative purposes, as flow channels, drag reduction structures,abrasive backings, etc.

The helical nature of the wrapped wires is illustrated in FIG. 1. Thecoils are preferably oriented at a helix angle a (alpha) relative to areference line that is normal to the surface of the cylindrical toolroll 10. As a result of the helical nature of the wrapped wires, theyprogress across the surface of the roll 10 from one end to the oppositeend. The helix angle a (alpha) is preferably rather small, e.g., about 5degrees or less, although larger helix angles could be used. Smallerhelix angles will typically result in smaller spacing between the moldcavities along the longitudinal axis 11 of the tool roll 10.Alternatively, the wires may be wrapped around the roll in an undulatinghelical pattern as described, e.g., in U.S. Pat. No. 6,767,202.

The illustrated tool roll 10 is manufactured using a cylindrical baseroll 12 around which a continuous wire 20 including depressions 26 and aspacer wire 40 are wound. The result is that alternating helical coilsof wire 20 with depressions 26 and spacer wire 40 are disposed over thesurface of the tool roll 10. The inner edges 24 of the wire 20 and theinner edge 44 of the spacer wire 40 are wrapped around the base roll 12while the outer edges 22 and 42 of the wires 20 and 40, respectively,are wound facing outward from the base roll 12. Both the wire 20 and thespacer wire 40 may preferably have rectangular cross-sections compatiblewith an even progression of the helical coils across the roll 10.

The wire 20 includes two major sides extending between the inner edge 24and the outer edge 22 of the wire 20. Although the wire 20 includesgenerally flat major sides, the major sides of wires used in connectionwith the present invention may take any suitable form. Some examples ofwires that include a variety of surfaces that, together form a majorside extending from an inner edge to an outer edge of a wire can be seenin FIGS. 8A-8D.

The depicted depressions 26 provided in a first major side 21 of wire 20include opposing side walls 27 a, 27 b, and 28 and bottom 29 as seen inFIG. 2. As used herein, the term “depression” is defined as a variationin a surface such that when the surface with the depression formedtherein is placed against a complementary surface without a depression,the depression forms a mold cavity. For example, a depression may be avoid or divot formed in the surface by displacing and/or removingmaterial such that the thickness of the structure orthogonal to thesurface varies across the surface. Depressions of the present inventiondo not extend through the opposing major sides of the wires.

Although depicted in FIG. 1 as having depressions formed in first majorside 21 of wire 20, the present invention may further include wires 20having depressions formed in both the first major side 21 and the secondopposing major side.

It may be preferred, but not required, that each of the depressions 26be of the same size and be evenly-spaced along the length of the wire 20to provide uniformity in the spacing of the resultant mold cavities 30.It may further be preferred that the outer edge 22 of the coils of wire20 is even with the outer edge 42 of the spacer wire 40 such that theareas between the mold cavities 30 in the finished tool roll 10 aresubstantially smooth, i.e., without significant discontinuities betweenthe wires 20 and 40.

Alternatively, the outer edges 22 and 42 of the wires 20 and 40,respectively, may be located at different heights above the surface ofthe base roll 12. Wires 20 and 40 with different heights can impart astructure to the surface of the article being manufactured. Thatstructure may be in the form of elongated ridges that may providereinforcement to, e.g., taller protrusions formed by the mold cavitiesand/or the article itself.

The wire 20, including depressions 26 formed therein that provide thedesired mold cavities 30 when wound around the base roll 12 as discussedabove, may preferably be manufactured using a wire or strip having agenerally rectangular cross-section. Wire 20 may be manufactured withthe depressions 26 or a wire with a substantially uniform profile mayfirst be manufactured and then processed by any suitable technique ortechniques to form the depressions 26 therein. The suitable technique ortechniques may include, but not limited to knurling, stamping,embossing, engraving, conventional machining, laser machining,electronic discharge machining, water jet machining, etching,photolithography, etc. The wire 20 may be manufactured from any suitablematerial or materials, although some preferred materials include steels,more preferably medium to low carbon steels.

The mold cavities 30 illustrated in FIGS. 1 & 2, which each include amold opening 31, have substantially uniform cross-sectional areas alongtheir depth from the opening at the surface of the tool roll 10 to themold cavity bottoms 29. The mold cavity bottoms 29 are formed by themold cavity 26 and an outer surface of the cylindrical base roll 12.FIG. 3A is an enlarged plan view of a few mold cavities 30 and FIGS. 3Band 3C are cross-sectional views of the mold cavities 30 along lines3B-3B and 3C-3C, respectively. The mold cavities 30 may exhibitgenerally rectilinear tangential cross-sectional areas along theirdepths d. By tangential, it is meant that the cross-section is takenalong a tangent to the roll 10. By rectilinear, it is meant that theshape of the mold cavity 30 in the tangential cross-section is formed bysubstantially planar sides. The illustrated cavities 30 are alsooriented substantially along the radius of the roll 10, although variousorientations are possible as discussed below.

Sides 27 a, 27 b, and 28 of the mold cavities 30 may be parallel or theymay be formed with a draft angle such that sides 27 a and 27 b arefarther apart at the openings of the mold cavities 30 than at thebottoms of the mold cavities 30 or vice versa.

In addition to controlling the shape of the depressions formed in themajor side of a wire, the present invention also provides control of thedepth of the depressions into the major side of the wire such that thewidth of the protrusions (e.g., width w′ of FIG. 1A) formed may beadjusted. The depth w of a mold cavity 30 into the major side of thewire 20 is seen in FIG. 3A.

In those instances, however, where the mold cavities have non-uniformshapes, e.g., the cavities are formed in the shape of hook or otherstructure, the “bottom” of the mold cavity is defined as the portion ofthe mold cavity that is closest to the outer surface of the cylindricalbase roll. One example of such a mold cavity is illustrated in FIG. 6Cwhere the mold cavity 230 c has a bottom 229 c closest to an outersurface 230 c of the cylindrical base roll 212. Furthermore, the depthd, of the mold cavity 230 c is also defined by the bottom 229 c of themold cavity 230 c. The mold cavity 230 c has an end 231 c that isdistinguishable from its bottom 229 c because the mold cavity 230 cturns away from the inner edge 224 c of the wire 220 c.

Although the bottoms of the various illustrative mold cavities describedabove are formed by the base rolls, it should be understood that thedepressions may terminate above the surface of the base roll, such thatthe bottom of the mold cavity is formed within the surface in which thedepression is formed.

One advantage of tool rolls manufactured according to the presentinvention as compared to tool rolls manufactured according to theteachings of U.S. Pat. No. 6,190,594 B1 (Gorman) and U.S. Pat. No.6,767,202 is that by using depressions formed in a surface of the wireto define the mold cavities, the mold cavity density may besubstantially increased. The increased mold cavity density may bepossible because of the ability to provide smaller mold cavities and tospace the mold cavities closer together along the length of the wire.

Tool rolls manufactured according to the present invention may include adensity of at least 50 cavities per cm² or more. It may be preferredthat the tool roll 10 include a density of at least 100 cavities per cm²or more. It may be more preferred that the tool roll 10 include adensity of at least 500 cavities per cm² or more.

The size of the mold cavity openings at the surface of the tool may berelatively small in relation to, e.g., the thickness of the wire. Forexample, the tangential cross-sectional area of the mold cavity openingsmay be 0.1 cm² or smaller, in some instances 0.02 cm² or smaller.

The preferred cylindrical base rolls 12 are precision formed to havetightly controlled runouts. That precision runout, in combination with atightly controlled height dimension h in the wires 20 can provide moldcavities 30 with substantially uniform depths d as measured from theouter surface of the roll 10. The tolerances to which the heightdimension h can be controlled will generally be relatively small and therunout of the base roll 12 can be tightly controlled, resulting inoverall tight tolerance control in the finished tool roll 10.

The mold cavities 30 can also be characterized in terms of aspect ratioas discussed above in connection with protrusions 72 on article 70 inFIG. 1A. The aspect ratio of the mold cavities 30 will be determinedbased on the depth d as compared to the minimum width w (see FIG. 3A) ofthe mold cavities, where the minimum width w is measured in a planetangential to the surface of the base roll 12 at the opening of the moldcavity. In other words, the aspect ratio of the mold cavities 30 is d:wand, where the tool roll 10 is to be used to manufacture articles havinga structured surface with high aspect ratio topology, it may bepreferred that the ratio d:w be, e.g., at least about 2:1 or higher,more preferably at least about 3:1 or higher, and even more preferablyat least about 5:1 or higher. In addition to, or in place of, highaspect ratio as defined above, it may be preferred that the mold cavitydepth d be, e.g., about 0.1 millimeters or more, more preferably about0.2 millimeters or more, and even more preferably about 0.4 millimetersor more.

FIGS. 3B and 3C illustrate another optional feature of the invention,namely the optional addition of a plating or other coating 50 on theroll 10. The illustrated coating 50 is located over the entire outersurface of the tool roll 10, i.e., the areas between the mold cavities30 as well as on the inner surface of the mold cavities 30.Alternatively, the coating could be located only on the outer surface ofthe roll 10 and absent from the inner surfaces of the cavities 30. Inanother alternative, the coating 50 could be located only in thecavities 30 and not on the outer surface of the roll 10. In stillanother alternative, a first coating could be located in the moldcavities 30 and a second coating could be located on the outer surfaceof the tool roll 10.

Although the coating 50 is illustrated as a homogenous layer, it shouldbe understood that coating 50 may actually be a combination of one ormore materials intermixed or applied in successive layers. The materialor materials used in coating 50 may vary depending on the desiredphysical properties. Some physical properties that may be desiredinclude, but are not limited to increased wear resistance, controlledrelease characteristics, controlled surface roughness, bonding betweenadjacent wire windings, etc. Some preferred materials may be metalplatings, more particularly an electroless nickel plating, chrome, etc.

FIGS. 4 and 5 depict another illustrative embodiment of a tool roll 110including mold cavities 130 opening into an outer surface of the toolroll 110. The tool roll 110 preferably includes a cylindrical base roll112 around which one or more wires are wrapped in the shape of a helicalcoil to produce a surface having a plurality of mold cavities 130 formedtherein.

As best illustrated in FIG. 5, the surface of the tool roll 110 can bewound with two wires 120 and 120′, each of the wires includingdepressions formed therein that, when wound together, form the moldcavities 130. One difference between the tool roll 110 and roll 10 isthat instead of a spacer wire 40 with a substantially uniformcross-section, the roll 110 includes two wires that both includedepressions formed therein. One advantage of the design of tool roll 110is the ability to provide higher density mold cavities 130, i.e.,reduced spacing between the mold cavities 130.

Although the illustrated tool roll 110 is preferably provided using twowires 120 and 120′, it will be understood that the tool roll 110 couldbe produced using three or more wires. In yet another alternative, thetool roll 110 could be provided with a single wire in which case thereference numbers 120 and 120′ would designate alternate windings orcoils of the wire.

Another tool roll variation is depicted in FIG. 5A, a plan view of onetool roll surface, in which mold cavities 330 are formed as compositesof depressions 326 and 346 formed in two major sides of wires 320 and340 that face each other when wound around the base roll (not shown).Although the depressions 326 and 346 facing each other are depicted assymmetrical, it should be understood that the depressions used to formthe composite mold cavity 330 may be symmetrical or asymmetrical. Byproviding composite mold cavities formed by two or more depressions, itmay be possible to provide cavities with shapes and/or dimensions thatwould otherwise be difficult to achieve by depressions formed in theside surface of only one wire.

FIGS. 6A-6E illustrate various shapes for depressions in the wires usedin connection with the present invention that vary from thesubstantially uniform depressions discussed above. One advantage of thetool rolls according to the present invention is that the depressionscan be formed with different shapes and/or orientations to provide moldcavities that also have different shapes and/or orientations. Further,wires used with the present invention may include more than one shape ofdepression such that finished films having complex patterns ofprotrusions may be produced. It will be understood that use of some ofthese mold cavities to produce a finished film with desired protrusionswill depend on resin selections and process conditions.

The mold cavity 230 a in FIG. 6A has a varying cross-sectional area thatincreases from the opening of the cavity 230 a to the bottom 229 a. Theside walls 227 aand 228 a are diverging in that direction. As a result,the cavity 230 a has a tangential cross-sectional area proximate thebottom 229 a of the cavity 230 a that is larger than the tangentialcross-sectional area at the opening of the cavity 230 a.

FIG. 6B depicts a mold cavity 230 b in which the side walls 227 b and228 b provide the cavity 230 b with a varying width that reaches amaximum at some point between the opening of the cavity 230 b and thebottom 229 b of the cavity 230 b. In the illustrated cavity 230 b, thewidth w″ is at a maximum near the midpoint of the depth of the cavity230 b. If the thickness of the wire in which the cavity 230 b is formedis constant over the depth of the cavity, then the mold cavity 230 b canbe described as having a tangential cross-sectional area at its openingthat is smaller than the tangential cross-sectional area of the cavity230 b at some point below its opening.

FIG. 6C depicts yet another variation in the shape of the mold cavitiesthat can be provided in tool rolls of the present invention. Theillustrated mold cavity 230 c has a curved shape in the form of a hook.Mold cavities with that shape may be used to directly form hook stripswithout significant additional processing. FIG. 6D illustrates a moldcavity 230 d including a double-ended hook shape that may also be moldedby tool rolls according to the present invention.

FIG. 6E depicts a variation in the orientation of mold cavities suppliedin tool rolls according to the present invention. The mold cavity 230 eis formed with an axis 231 e that is oriented at an angle with respectto the radius r of the tool roll (not shown).

FIG. 6F depicts a mold cavity 230 f in which the side walls 227 f and228 f provide the cavity 230 f with a varying width that tapers at somepoint between the opening of the cavity 230 f and the bottom 229 f ofthe cavity 230 f. In other words, the cavity 230 f can be described ashaving a tangential cross-sectional area at its opening that is largerat the opening than the tangential cross-sectional area of the cavity230 f then at some point below its opening; the cavity 230 f narrows asthe cavity 230 f progresses from outer edge 222 f of wire 220 f to inneredge 224 f.

The present invention may also include bleed structures formed in asurface of the wire or wires used to form the mold cavities. The bleedstructures may allow fluid (e.g., air) to more readily escape from themold cavities, thereby enhancing filling of the cavities. The bleedstructures may be particularly helpful when the mold cavities havehigher aspect ratios that could otherwise be difficult to fillcompletely.

It may be preferred that the bleed structures occupy only a portion ofthe surface of the wire such that an edge zone is provided proximate theouter surface of the tool roll. The edge zone is preferably free of thebleed structure to prevent undesired filling of the bleed structure bythe moldable material during processing.

Furthermore, although the bleed structure is depicted in FIG. 6F asbeing formed in the same surface as the depression that forms moldcavity 230 f, it should be understood that the bleed structure couldalternatively be located on the surface that faces the depressionforming mold cavity 230 f. With respect to FIG. 2, a bleed structurecould be located on the surface of the spacer wire 40 that faces thedepressions 26. With respect to FIG. 5, a bleed structure could beformed in the opposite side of the wire 120 and 120′ from the side inwhich the depressions forming mold cavities 130 are formed. In anotheralternative, a bleed structure could be provided on both of the surfacesused to define mold cavities in accordance with the principles of thepresent invention.

The depicted bleed structure 225 f formed in the first major side 221 fof wire 220 f is a knurl pattern that essentially defines channels 226 fthat intersect sidewalls 227 f and 228 f of mold cavity 230 f. It may bepreferred that channels 226 f are of a size such that significantamounts of moldable material may not be able to enter the bleedstructure 225 f. The bleed structure 225 f may preferably extend to theinner edge 224 f of wire 220 f to provide pathways for fluid to exit themold cavity 230 f.

Further, it may be preferred that bleed structure 225 f does not extendinto an edge zone 223 f proximate the outer edge 222 f of the wire 220f. By providing an edge zone 223 f free of the bleed structure 225 f ,the channels 226 f do not form cavities with openings on the outersurface of the tool roll that may be filled with moldable material. Insome instances, however, it may be possible to allow the bleed structureto extend to the outer edge 222 f of the wire 220 f where, for example,any openings thus formed are too small to significantly fill withmoldable material or where any such filling is acceptable.

In addition to (or in place of) bleed structures formed on the wire orwires wound around a base roll, the surface of the tool roll aroundwhich the wire or wires are wound may also include a bleed structure toassist in the removal of air or other fluids from the mold cavitiesduring processing. The bleed structure on the surface of the base rollmay be used alone (without bleed structures on the wires) where the moldcavities include bottoms that are formed by the outer surface of thebase roll itself, thereby placing the mold cavities in fluidcommunication with the bleed structure on base roll.

The outer surface 214 f of the base roll 212 f of FIG. 6F is depicted asincluding a bleed structure in the form or a randomly roughened surface(formed by, e.g., etching, sandblasting, etc.). The bleed structure ofsurface 214 f may extend over the entire surface 214 f of base roll 212f or it may be provided in only selected areas.

An additional advantage that may be provided by a base roll 212 fincluding a bleed structure formed on its outer surface 214 f is thatmay assist in holding wire 220 f in place around the cylindrical baseroll 212 f by increasing frictional forces developed between the wire220 f and the base roll 212 f.

The bleed structures used in connection with the present invention (onthe wires or the base roll) may be formed using any suitable techniqueknown in the art, e.g., knurling, stamping, embossing, engraving,conventional machining, laser machining, electronic discharge machining,water jet machining, etching, photolithography, etc. Further, althoughthe depicted bleed structures are a knurl pattern and a roughenedsurface, a bleed structure according to the present invention may beformed by any suitable structure or surface treatment that can provide apath for fluid to move between two facing surfaces, e.g., channels,standoffs that create voids, roughened surfaces (formed by etching,sandblasting, etc.), and combinations thereof.

FIG. 7A illustrates a tool roll 310 in a plan view that includes areas314 and 316 in which the mold cavities differ. In one example, areas 314may be provided with mold cavities while areas 316 may be substantiallyfree of mold cavities. In another example, the mold cavities in thedifferent areas 314 and 316 may be different. The areas 314 and 316 ontool roll 310 are depicted as having a substantially uniform width andpreferably also extend about the circumference of the roll 310.

Tool rolls according to the present invention may alternatively includeareas in which the mold cavities differ that are not uniformly shapedand/or that do not extend around the circumference of the roll 310. Onesuch variation is illustrated in FIG. 7B in which area 314′ is orientedalong the width of the tool roll 310′ and surrounded on either side byareas 316′. As such, area 314′ forms a longitudinal stripe along theroll 310′.

FIG. 7C illustrates another tool roll 310″ that also includes areas 314″that have either no mold cavities or mold cavities that differ in somerespect from the mold cavities in area 316″. The areas 314″ can take anyshape, e.g., a logo as shown. Methods of manufacturing the tool roll310″ may include manufacturing a tool roll that includes uniformlyshaped mold cavities distributed uniformly over its entire surface.After manufacturing the tool roll 310″ with uniform mold cavities, oneor more portions (e.g., areas 314″) of the surface of the tool roll 310″can be masked while the other portion or portions (e.g., area 316″) isprocessed to differentiate the mold cavities within the areas 314″ fromthe mold cavities within the area 316″. One method of processing thetool roll 310″ could include, e.g., filling the mold cavities in theunmasked area either partially or completely. The materials used forfilling could include solder, plastics, wax, etc. The materials usedcould be permanently located within the mold cavities or they may beremovable to allow reuse of the tool roll with, e.g., a different logo.

FIGS. 8A-8D illustrate more variations in the wires used to form themold cavities in the tool rolls of the present invention. Thecross-sections are taken transverse to the lengths of the wires and, inFIG. 8A, the wire 420 a is provided with a reverse L-shapedcross-section while the spacer wire 440 a fits within the space formedbetween abutting wires 420 a.

In FIG. 8B the wires 420 b and 440 b have mating profiles. In addition,wires 440 b include a non-planar surface 442 b that, in the illustratedembodiment, is a curved surface. Where the wires 420 b includedepressions that form the desired mold cavities (not shown), theaddition of a curvature to the outer surface 442 b of wires 440 b mayproduce a corresponding fillet on two sides of the base of the eachprotrusion formed by the mold cavities. That fillet may improve thestrength of the protrusion, i.e., increase its resistance to deflection.In addition, the curvature may also produce a ridged structure betweenprotrusions that may impart additional rigidity to the film or article.

Wires 420 c and 440 c in FIG. 8C illustrate wires with mating profilesthat also include tapered sides. FIG. 8D illustrates wires 420 d and 440d that have nested profiles.

Using a wire or wires that include mating or nesting profiles asillustrated in FIGS. 8A-8D may improve the integrity of the windings onthe base roll as the finished tool rolls are subjected to stressesduring manufacture and use as a molding tool. Many other variations inthe wire profiles may be envisioned within the scope of the presentinvention.

FIG. 9 illustrates one process of winding a base roll 512 with a wire520 including depressions 526 and a spacer wire 540 to provide a toolroll 510 including mold cavities 530. It will be understood that morethan two wires may be wound together if so desired.

In the methods of manufacturing tool rolls according to the presentinvention, it may be desirable to machine the outer surface of the toolroll 510 after winding the wires 520 and 540 to provide improved runoutin the finished tool roll 510.

It may also be desirable to remove any burrs remaining from, e.g., wirepunching and/or machining of the wound roll, by blasting the roll withsodium bicarbonate (baking soda) or a similar material. The finishedtool roll 510 may also be processed to provide a desired surface finishwithin the mold cavities 530 and/or on the outer surface of the toolroll 510 between the mold cavities 530. For example, it may be desirableto chemically etch, sandblast, plate, coat or otherwise modify thesurfaces of the tool roll 510.

FIG. 10 illustrates one process in which a tool roll 610 according tothe present invention can be used to form a high aspect topology film. Amoldable material 660 can be applied to the surface of the tool roll 610by, e.g., extrusion or cast molding to create a film 670 includingprotrusions 672 that are replicas of the mold cavities in the tool roll610. In preferred embodiments, adhesion of the material 660 to the toolroll 610 is less than the cohesion within the material 660 at the timeof removal from the tool roll 610. It may be further preferred that theadhesion of the material 660 to the tool roll not exceed the tensilestrength of the wire or wires used to form the tool roll 610.

Substantially any moldable material may be used in connection with thepresent invention. It may be preferred that the moldable material be anorientable thermoplastic resin. Orientable thermoplastic resins that canbe extrusion molded and should be useful include polyesters such aspoly(ethylene terephthalate), polyamides such as nylon,poly(styrene-acrylonitrile), poly(acrylonitrile-butadiene-styrene),polyolefins such as polypropylene, and plasticized polyvinyl chloride.One preferred thermoplastic resin is an impact copolymer ofpolypropylene and polyethylene containing 17.5% polyethylene and havinga melt flow index of 30, that is available as SRD7-587 from UnionCarbide, Danbury, Conn. The thermoplastic resin may also compriseblends, including polyethylene and polypropylene blends, co-polymers,such as polypropylene-polyethylene co-polymers, or coextruded asmultiple layers or in alternating zones. Additives such as plasticizers,fillers, pigments, dyes, anti-oxidants, release agents, and the like mayalso be incorporated into the moldable material.

In one preferred process, the material 660 is provided by extrusion intoa nip formed by the tool roll 610 and a backup roll 680. The backup roll680 preferably provides some pressure to assist in forcing the moldablematerial 660 into the mold cavities 630 (see FIG. 11) provided in thetool roll 610. Alternatively, the backup roll 680 may be replaced by anycontinuously moving surface that can assist in forcing the mold materialinto the mold cavities in tool roll 610.

The interior of the tool roll 610 may be supplied with a vacuum toassist in removal of air that may otherwise interfere with completefilling of the mold cavities. However, in many instances, no vacuum maybe supplied as the air within the mold cavities escapes between thewires used to manufacture the tool roll 610. In other words, the processmay be performed in the absence of a vacuum.

It may also be desirable to provide some thermal control in either orboth of the tool roll 610 and the backup roll 680. Depending on processconditions, temperatures of the moldable material 660, properties of themoldable material 660, etc. it may be desirable to either heat one orboth of the rolls 610 and 680, cool one or both of the rolls 610 and680, or heat one of the rolls and cool the other roll.

After the material 660 is forced within the mold cavities in tool roll610 and has sufficiently cooled to form a film 670 with protrusions 672that can maintain the desired shape or shapes, it is stripped from thetool roll 610 for further processing or the film 670 can be wound intorolls. For example, if mechanical fastener strips are desired, the film674 may be directed into a station or stations to modify theprotrusions, coat adhesives, and perform other processing as discussedin, e.g., U.S. Pat. Nos. 5,845,375 (Miller et al.), 5,077,870 (Melbye etal.), PCT Publication Nos. WO 98/57565; WO 98/57564; WO 98/30381; and WO98/14086.

It may be desirable to direct one or more additional materials into thenip formed by the tool roll 610 and backup roll 680 to provide desiredadditional properties to the film 670. For example, a woven or nonwovenweb may be directed into the nip. Alternatively, the film 670 may belaminated to one or more additional layers by, e.g., heat, adhesives,coextrusion, etc.

FIG. 11 is a cross-sectional view of the apparatus of FIG. 10 takenalong line 11-11 in FIG. 10. The tool roll 610 includes mold cavities630 filled by the moldable material to form protrusions 672 on film 670.Also illustrated in FIG. 11 are two raised structures 682 formed on thebackup roll 680. One advantage of the raised structures 682 on theillustrated backup roll 680 is that each of the raised structures maycreate a line or zone of weakness along which the film 670 can beseparated. The raised structures 682 are, however, optional and need notbe provided in connection with the present invention.

Another optional feature that may be incorporated into the backup roll680 is the addition of some structure to the surface of the roll 680 toincrease its surface area. The increased surface area on the backup roll680 can increase the surface area on the film 670, thereby improvingadhesion of any adhesives provided on the back side 674 of the film 670.One example of useful structure could be a micro-embossed pattern oflinear prisms on the scale of about 400 lines per inch (160 lines percentimeter).

FIG. 12 illustrates another process using wire-wound tool rolls withmold cavities formed therein. The illustrated process forms a film 770having protrusions 772 extending from one side thereof and protrusions772′ extending from the opposite side of the film 770. The two-sidedfilm 770 is formed by opposing tool rolls 710 and 710′, both of whichinclude mold cavities formed therein. The protrusions 772 and 772′ mayhave the same characteristics in terms of size, shape, orientation, etc.or they may be different.

FIGS. 13 & 14 depict still another embodiment of a tool roll that may beprovided in connection with the present invention. FIG. 13 is a planview of a portion of a tool roll formed by wrapping wires 820 and 840 ina helical pattern about the surface of a base roll. Although the toolroll may include different wires 820 and 840, only a single wire couldbe provided, in which case the reference numbers 820 and 840 woulddesignate alternate windings or coils of the wire. Further, more thantwo wires could be wound around a tool roll in accordance with thepresent invention.

In the depicted embodiment, wire 820 includes a plurality of voids 890formed through both of its major sides 821 and 825 (although only onesuch void is depicted in FIG. 13), the void 890 also taking a portion ofthe outer edge 822 of the wire 820. The void 890 does not, however,extend to the inner edge 824 of the wire 820. In addition to the void890, depressions 830 a and 830 b are also formed in the major sides 821and 825 of the wire 820. The depressions 830 a and 830 b open into thevoid 890. The void 890 and the depressions 830 a and 830 b may togetherprovide a composite mold cavity with a shape that could not be achievedwith a void alone or with only depressions.

A tool roll formed using wires 820 and 840 will include a plurality ofcomposite mold cavities formed therein. Furthermore, it will beunderstood that each void 890 may be provided in connection with onlyone depression or more than two depressions if so desired, i.e., thecomposite mold cavities are not to be limited to structures formed by avoid in combination with two depressions.

FIG. 15 is a perspective view of a protrusion 872 that may be formedusing the composite mold cavity depicted in FIGS. 13 & 14. Theprotrusion 872 includes a stem 871 protruding from a surface 874 ofarticle 870. The stem 871 is formed primarily by the void 890 formed inwire 820. A pair of ears 873 and 875 extend from the stem 871. The ears873 and 875 are formed primarily by the depressions 830 a and 830 b inwire 820 as described above.

In some instances, protrusions 872 may be useful in their as-formedshape seen in FIG. 15. In other instances, however, it may beadvantageous to modify the shape of the protrusion 872 from itsoriginally-formed shape. One such modification is depicted in FIG. 16where the protrusion 872 is depicted as extending from surface 874 ofarticle 870. The stem 871 remains essentially unchanged, but the ears873 and 875 have been modified such that they no longer stand verticallyrelative to the localized plane defined by surface 874. Rather, the ears873 and 875 have been processed such that they extend horizontallyrelative to the localized plane defined by surface 874. In thisconfiguration, the protrusion 872 may be useful as, e.g., a mechanicalfastener with ears 873 & 875 serving as hooks that may engage acomplementary structure (e.g., a loop structure). Examples of processesthat may be used to accomplish this change include, e.g., theapplication of heat or the application of heat and mechanical pressure.

FIGS. 17-19 depict another embodiment of a tool roll including compositemold cavities formed by voids and depressions in wires. The structuredepicted in FIG. 17 includes wires 920 and 940 that may be the same ordifferent wires as described above with respect to FIG. 13. The wire 920includes a plurality of voids 990 formed through its two major sides 921and 925 (although only one such void is depicted in the view of FIG.17). A view of one major side of wire 940 a is depicted in FIG. 19,illustrating that the depression formed extends from outer edge 942 toinner edge 944 (the edge that is wound against the surface of a baseroll (not shown). Alternatively, the depression 930 a may not extendfrom the outer edge 942 to the inner edge 944 of wire 940 a.

One variation from the structure of FIG. 13 is that the wires 940include depressions 930 a and 930 b formed in their respective majorsides, such that the depressions 930 a and 930 b face the major sides ofwire 920. This differs from the structures seen in FIGS. 13 & 14, inwhich both the void 890 and depressions 830 a and 830 b are formed inthe wire 820, with wires 840 having generally flat sides (although theymay include bleed structures as discussed herein).

It may be preferred that the depressions 930 a and 930 b intersect withthe void 990 as seen in FIG. 17 such that the depressions 930 a and 930b form a composite mold cavity including the volumes defined by the void990 in wire 920 and the depressions 930 a and 930 b in wires 940.Further, although only one composite mold cavity is depicted in FIG. 17,it will be understood that tool rolls manufactured using wires 920 and940 will include a plurality of composite mold cavities dispersed overthe surface of the roll.

FIG. 20 is a perspective view of a protrusion 972 that may be formedusing the composite mold cavity depicted in FIGS. 17 & 18. Theprotrusion 972 includes a stem 971 protruding from a surface 974 ofarticle 970. The stem 971 is formed primarily by the void 990 formed inwire 920. A pair of ribs 973 and 975 extend along opposite sides of thestem 971 and extend past the height of the stem 971. The ribs 973 and975 are formed primarily by the depressions 930 a and 930 b in wires 940a and 940 b (respectively) as described above.

In some instances, protrusions 972 may be useful in their as-formedshape seen in FIG. 20. For example, the ribs 973 and 974 may enhance therigidity or structural integrity of the protrusion 972. In otherinstances, however, it may be advantageous to modify the shape of theprotrusion 972 from its originally-formed shape. One such modificationis depicted in FIG. 21 where the stem 971 of protrusion 972 remainsessentially unchanged, but the portions of the ribs 973 and 975 thatextend past the stem 971 have been modified such that they no longerstand vertically relative to the localized plane defined by surface 974.Rather, the ribs 973 and 975 have been processed such that they extendhorizontally relative to the localized plane defined by surface 974. Inthis configuration, the protrusion 972 may be useful as, e.g., amechanical fastener with the portions of the ribs 973 & 975 extendingfrom the stem 971 serving as hooks that may engage a complementarystructure (e.g., a loop structure). Examples of processes that may beused to accomplish this change include, e.g., the application of heat orthe application f heat and mechanical pressure.

FIG. 22 is a perspective view of another article 1070 of the presentinvention including protrusions formed of ridge 1071 extending from asurface 1074 of the article 1070. Each of the ridges 1071 includes aplurality of ears 1073 protruding therefrom. In some instances, the ears1073 may be useful in their as-formed shape seen in FIG. 22. In otherinstances, however, it may be advantageous to modify the shape of theears 1073 as depicted and described with respect to, e.g., FIGS. 16 &21. The ridge 1071 of each protrusion may preferably have a length (indirection 1011) that is coextensive with the length of the article 1070in direction 1011. Alternatively, the ridge 1071 of each protrusion mayhave a length shorter than that of article 1070. The length of eachridge 1071 in direction 1011 may preferably be greater than its width(measured transverse to direction 1011), e.g., it may be preferred thatthe length of the ridge 1071 be at least two or more times the width ofthe base 1071. Furthermore, it may be preferred that the elongatedridges 1071 be aligned with each other along a common direction, e.g.,direction 1011 in FIG. 22.

FIG. 23 is a plan view of a portion of a tool roll 1010 and FIG. 24 isan enlarged cross-sectional view of the tool roll 1010 taken along line24-24 in FIG. 23. The tool roll 1010 may be used to manufacture anarticle such as that depicted in FIG. 22. Tool roll 1010 is formed bywires 1020 and 1040 that are helically wound around a base roll 1012.Wire 1020 has an outer edge 1022 with a height above the base roll 1012that is less than the height of the outer edge 1042 of the wire 1040,resulting in a tool roll 1010 on which grooves are formed betweenwindings of wire 1040. The grooves formed between windings of wires 1040provide the mold cavities in which ridges 1071 of article 1070 can beformed when tool roll 1010 is contacted by moldable material. Althoughwires 1020 and 1040 are disclosed as having generally rectangularprofiles, they could alternately be provided with a different shape, inwhich case the ridges 1071 of article 1070 would also be formed with adifferent shape than that illustrated in FIG. 22.

Also seen in FIGS. 23 and 24 are depressions 1030 formed in wires 1020.The depressions 1030 fill with moldable material to form ears 1073 onridges 1071 as seen in FIG. 22. Although depressions 1030 are shown onlyin wire 1020, it will be understood that depressions may be provided ineither wire 1020, wire 1040, or both wire 1020 and wire 1040. Althoughnot seen in FIGS. 23 and 24, one or both of wires 1020 and 1040 maypreferably include bleed structures as described herein.

Although the grooves formed by the wires 1020 and 1040 wrapped aroundthe tool roll 1010 may be continuous around the circumference of theroll 1010, they may also be discontinuous. FIG. 25 depicts a tool roll1110 including grooves 1190 that extend for some length around the toolroll 1110, but are not formed in a continuous helical groove. Theelongated grooves 1190 can, e.g., be formed by wires including voidsformed therein as discussed above with respect to, e.g., FIGS. 13 & 14.The voids in the wires used in tool roll 1110 will, however, typicallyextend for longer distances over the length of the wires.

These elongated voids may be uniformly sized and spaced as depicted inthe tool rolls above, or they may be non-uniformly sized andnon-uniformly spaced. Tool roll 1110 illustrates wires withnon-uniformly sized and spaced voids that, when wrapped around a baseroll, form non-uniformly sized and spaced grooves 1190.

The articles produced by a tool roll such as tool roll 1110 will includeelongated ridges 1171 as illustrated in FIG. 26. The ridges 1171preferably include protrusions (not shown) formed thereon such as thosedepicted in connection with FIGS. 15, 20, and 22. Because the grooves1190 in tool roll 1110 are non-uniformly sized and spaced, the elongatedridges 1171 on article 1170 are also non-uniformly sized and spaced.

All patents, patent applications, and publications cited herein are eachincorporated herein by reference in their entirety, as if individuallyincorporated by reference. Various modifications and alterations of thisinvention will become apparent to those skilled in the art withoutdeparting from the scope of this invention, and it should be understoodthat this invention is not to be unduly limited to the illustrativeembodiments set forth herein.

1. An article comprising: a base surface; a plurality of elongatedridges protruding from the base surface; and a plurality of earsprotruding from each elongated ridge of the plurality of elongatedridges.
 2. An article according to claim 1, wherein each elongated ridgeof the plurality of elongated ridges is coextensive with the article ina direction along which the elongated ridge extends.
 3. An articleaccording to claim 1, wherein the plurality of elongated ridges arealigned along a common direction.